/**
 *    Copyright 2009-2021 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.apache.ibatis.submitted.mapper_type_parameter;

import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.InsertProvider;
import org.apache.ibatis.annotations.MapKey;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.SelectProvider;
import org.apache.ibatis.annotations.UpdateProvider;

public interface BaseMapper<S, T> {

    @SelectProvider(type = StatementProvider.class, method = "provideSelect")
    S select(S param);

    @SelectProvider(type = StatementProvider.class, method = "provideSelect")
    List<S> selectList(S param);

    @SelectProvider(type = StatementProvider.class, method = "provideSelect")
    @MapKey("id")
    Map<T, S> selectMap(S param);

    @InsertProvider(type = StatementProvider.class, method = "provideInsert")
    @Options(useGeneratedKeys = true, keyProperty = "id")
    int insert(List<S> param);

    @UpdateProvider(type = StatementProvider.class, method = "provideUpdate")
    int update(S param);

    public class StatementProvider {
        public String provideSelect(Object param) {
            StringBuilder sql = new StringBuilder("select * from ");
            if (param == null || param instanceof Person) {
                sql.append(" person ");
                if (param != null && ((Person) param).getId() != null) {
                    sql.append(" where id = #{id}");
                }
            } else if (param instanceof Country) {
                sql.append(" country ");
                if (((Country) param).getId() != null) {
                    sql.append(" where id = #{id}");
                }
            }
            sql.append(" order by id");
            return sql.toString();
        }

        public String provideInsert(Map<String, Object> map) {
            List<?> params = (List<?>) map.get("list");
            StringBuilder sql = null;
            for (int i = 0; i < params.size(); i++) {
                Object param = params.get(i);
                if (sql == null) {
                    sql = new StringBuilder("insert into ");
                    sql.append(param instanceof Country ? " country " : " person");
                    sql.append(" (id, name) values ");
                } else {
                    sql.append(",");
                }
                sql.append(" (#{list[" + i + "].id}, #{list[" + i + "].name})");
            }
            return sql == null ? "" : sql.toString();
        }

        public String provideUpdate(Object param) {
            StringBuilder sql = new StringBuilder("update ");
            if (param instanceof Person) {
                sql.append(" person set name = #{name} where id = #{id}");
            } else if (param instanceof Country) {
                sql.append(" country set name = #{name} where id = #{id}");
            }
            return sql.toString();
        }
    }
}
